U.S. patent application number 15/050314 was filed with the patent office on 2016-06-16 for single-transceiver ultrasonic flow meter apparatus and methods.
The applicant listed for this patent is TEXAS INSTRUMENTS DEUTSCHLAND GMBH. Invention is credited to Matthieu Chevrier, Michael Weitz.
Application Number | 20160169721 15/050314 |
Document ID | / |
Family ID | 52342491 |
Filed Date | 2016-06-16 |
United States Patent
Application |
20160169721 |
Kind Code |
A1 |
Chevrier; Matthieu ; et
al. |
June 16, 2016 |
SINGLE-TRANSCEIVER ULTRASONIC FLOW METER APPARATUS AND METHODS
Abstract
Elements of a single beam-forming array of ultrasonic transducer
elements are selectively activated to direct two or more ultrasonic
beams to a series of acoustic mirrors mounted to or fabricated at
known locations at an inside surface of the pipe. The ultrasonic
beams traverse measurement path segments at known angles through a
fluid flowing through the pipe before being received back at the
single transducer array. Fluid flow velocity along the fluid flow
path is calculated as a function of a difference in time-of-flight
(TOF) along first and second ultrasonic beam paths after
subtracting TOF components contributed by known-length
non-measurement path segments. The difference in TOF results from
an additive downstream fluid flow velocity vector component along a
first measurement path segment and a subtractive upstream fluid
flow velocity vector component along a second measurement path
segment.
Inventors: |
Chevrier; Matthieu;
(Freising, DE) ; Weitz; Michael; (Wangen,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TEXAS INSTRUMENTS DEUTSCHLAND GMBH |
Freising |
|
DE |
|
|
Family ID: |
52342491 |
Appl. No.: |
15/050314 |
Filed: |
February 22, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14072605 |
Nov 5, 2013 |
9267829 |
|
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15050314 |
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61856387 |
Jul 19, 2013 |
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61866467 |
Aug 15, 2013 |
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Current U.S.
Class: |
73/861.31 |
Current CPC
Class: |
H02H 9/025 20130101;
G01F 1/667 20130101; H02H 9/005 20130101; G01F 1/662 20130101 |
International
Class: |
G01F 1/66 20060101
G01F001/66 |
Claims
1. A fluid flow measurement apparatus, comprising: a beam-forming
array of ultrasonic transducer elements capable of mounting at a
single position at a wall of a pipe to provide directional control
of ultrasonic energy emitted from the array of transducer elements
and received at the array of transducer elements; and a
beam-forming driver circuit communicatively coupled to the
beam-forming array of ultrasonic transducer elements to selectively
activate at least one first sub-array of the array of transducer
elements such as to direct at least two outbound ultrasonic beams
through a fluid flowing through the pipe to at least one acoustic
mirror mounted at an inside wall of the pipe and to selectively
activate at least one second sub-array of transducer elements to
sense a reflected return signal associated with each of the at
least two outbound ultrasonic beams at a selected angle.
2. The fluid flow measurement apparatus of claim 1, further
comprising: a control and measurement module communicatively
coupled to the beam-forming array of ultrasonic transducer elements
to measure a time-of-flight (TOF) of the at least two ultrasonic
beams from emission from the array of ultrasonic elements to
reception of the return signal at the array of ultrasonic elements
and to calculate a fluid flow speed as a function of a difference
in TOF between a first of the at least two ultrasonic beams capable
of traversing a first path and a second of the at least two
ultrasonic beam capable of traversing a second path, at least a
portion of the difference in TOF a result of an additive downstream
fluid flow velocity vector component along a first path measurement
segment traversing the fluid at an angle less than 90 degrees from
a longitudinal axis of the pipe and a subtractive upstream fluid
flow velocity vector component along a second path measurement
segment traversing the fluid at the angle less than 90 degrees from
the longitudinal axis of the pipe.
3. The fluid flow measurement apparatus of claim 2, the first and
second path measurement segments of equal length and the downstream
and upstream fluid flow velocity components of equal magnitude and
opposite direction.
4. The fluid flow measurement apparatus of claim 1, the first and
second sub-arrays of transducer elements consisting of the same
elements.
5. The fluid flow measurement apparatus of claim 1, the at least
one acoustic mirror configured to reflect the first and second
ultrasonic beams along the inside wall of the pipe where the flow
rate of the fluid is substantially zero.
6. The fluid flow measurement apparatus of claim 1, the
beam-forming array of ultrasonic transducer elements formed as at
least one of a single-dimensional array, a two-dimensional array,
or a three-dimensional array.
7. The fluid flow measurement apparatus of claim 1, the
beam-forming array of transducer elements formed as a plurality of
sub-arrays of transducer elements capable of projecting the
ultrasonic beams along beam path segments extending from and/or to
the beam-forming array of transducer elements both parallel to the
longitudinal axis of the pipe and perpendicular to the longitudinal
axis of the pipe.
8. The fluid flow measurement apparatus of claim 1, at least one
transducer element of the array of transducer elements selected
from a group consisting of a bulk piezoelectric transducer element,
a capacitive micro-machined ultrasonic transducer (CMUT) element,
and a piezoelectric micro-machined ultrasonic transducer (PMUT)
element.
9. The fluid flow measurement apparatus of claim 1, the at least
one acoustic mirror formed by a portion of the inside wall of the
pipe.
10. A method of fluid flow measurement, comprising: selectively
activating elements of an array of transducer elements capable of
mounting at a single position at a wall of a pipe to create a first
ultrasonic beam directed toward an acoustic mirror associated with
a first series of acoustic mirrors at a first time; directing the
first ultrasonic beam along a first path to include at least one
first path measurement segment to traverse a fluid flowing through
the pipe at an angle less than 90 degrees from a longitudinal axis
of the pipe in a direction to include an additive downstream fluid
flow velocity vector component; receiving a return of the first
ultrasonic beam at the array of transducer elements at a second
time; at the array of transducer elements, creating a second
ultrasonic beam directed toward an acoustic mirror associated with
a second series of acoustic mirrors at a third time; directing the
second ultrasonic beam along a second path to include at least one
second path measurement segment to traverse the fluid flowing
through the pipe at the angle less than 90 degrees from the
longitudinal axis of the pipe in a direction to include a
subtractive upstream fluid flow velocity vector component;
receiving a return of the second ultrasonic beam at the array of
transducer elements at a fourth time; calculating a fluid flow
speed as a function of a difference in time-of-flight (TOF) between
the first and second ultrasonic beams, at least a portion of the
difference in TOF a result of the additive downstream fluid flow
velocity vector component along the first path measurement segment
and the subtractive upstream fluid flow velocity vector component
along the second path measurement segment.
11. The method of fluid flow measurement of claim 10, the first and
second paths of equal length and the downstream and upstream fluid
flow velocity vector components of equal magnitude and opposite
direction.
12. The method of fluid flow measurement of claim 10, further
comprising: reflecting the first and second ultrasonic beams along
the inside wall of the pipe where the flow rate of the fluid is
substantially zero.
13. The method of fluid flow measurement of claim 10, further
comprising: reflecting the first and second ultrasonic beams within
an enclosed channel formed along the inside wall of the pipe to
isolate the first and second ultrasonic beams from the fluid.
14. The method of fluid flow measurement of claim 10, the first and
second paths to each include a segment orthogonal to the
longitudinal axis of the pipe and a segment extending along the
inside wall of the pipe where the flow rate of the fluid is
substantially zero, the first path to additionally include the
first path measurement segment and the second path to additionally
include the second path measurement segment.
15. The method of fluid flow measurement of claim 10, further
comprising: traversing the first path measurement segment between
the array of transducer elements and a first acoustic mirror; and
traversing the second path measurement segment between the array of
transducer elements and a second acoustic mirror.
16. The method of fluid flow measurement of claim 10, further
comprising: traversing the first and second path measurement
segments between two acoustic mirrors.
17. The method of fluid flow measurement of claim 10, further
comprising: traversing the first and second path measurement
segments between the array of transducer elements and at least one
of a single acoustic mirror or an inner wall of the pipe opposite
the array of transducer elements.
18. A method of fluid flow measurement, comprising: selectively
activating elements of an array of transducer elements capable of
mounting at a single position at a wall of a pipe to create a first
ultrasonic beam and a second ultrasonic beam at a first time, the
first ultrasonic beam directed toward an acoustic mirror associated
with a first series of acoustic mirrors and the second ultrasonic
beam directed toward an acoustic mirror associated with a second
series of acoustic mirrors; directing the first ultrasonic beam
along a first path to include at least one first path measurement
segment to traverse a fluid flowing through the pipe at an angle
less than 90 degrees from a longitudinal axis of the pipe in a
direction to include an additive downstream fluid flow velocity
vector component; receiving a return of the first ultrasonic beam
at the array of transducer elements at a second time; directing the
second ultrasonic beam along a second path to include at least one
second path measurement segment to traverse the fluid flowing
through the pipe at the angle less than 90 degrees from the
longitudinal axis of the pipe in a direction to include a
subtractive upstream fluid flow velocity vector component;
receiving a return of the second ultrasonic beam at the array of
transducer elements at a third time; and calculating a fluid flow
speed as a function of a difference in time-of-flight (TOF) between
the first and second ultrasonic beams, at least a portion of the
difference in TOF a result of the additive downstream fluid flow
velocity vector component along the first path measurement segment
and the subtractive upstream fluid flow velocity vector component
along the second path measurement segment.
19. The method of fluid flow measurement of claim 18, further
comprising: differentiating the respective return signals from the
first and second ultrasonic beams based upon interference patterns
associated with the respective returns as sensed at the array of
transducer elements.
20. The method of fluid flow measurement of claim 18, further
comprising: differentiating the respective return signals from the
first and second ultrasonic beams by emitting the first ultrasonic
beam at a frequency distinct from a frequency used to emit the
second ultrasonic beam.
Description
PRIORITY CLAIM
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/072,605 filed Nov. 5, 2013, which claims
the benefit of U.S. Provisional Patent Application Ser. No.
61/856,387, filed on Jul. 19, 2013, and U.S. Provisional Patent
Application Ser. No. 61/866,467, filed on Aug. 15, 2013, all of
which are incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] Structures and methods described herein relate to the
measurement of fluid flow rates in pipes and tubing, including
comparing the time-of-flight (TOF) of ultrasonic pulses sent
through the fluid to detect downstream and upstream fluid velocity
contributions to the TOF.
BACKGROUND INFORMATION
[0003] FIG. 1 is a prior-art diagram illustrating a fluid-flow
measurement technique according to the prior art. A first
ultrasonic transducer 110 is located at a wall 115 of a pipe 120
upstream from a second ultrasonic transducer 125 located further
downstream at a wall 130 of the pipe 120.
[0004] A first ultrasonic signal is emitted from the upstream
transducer 110 and received at the downstream transducer 125 across
a path 135A. A time-of-flight (TOF) T(1,2) between emission and
reception of the first ultrasonic signal is measured. A second
ultrasonic signal is emitted from the downstream transducer 125 and
received at the upstream transducer 110 across a path 135B. A TOF
T(2,1) between emission and reception of the second ultrasonic
signal is measured. The paths 135A and 135B are of equal length L.
Each of the paths 135A and 135B lies at an angle .theta. to a
longitudinal axis of the pipe 120.
[0005] The velocity of the ultrasonic signal traveling at the angle
.theta. downstream is boosted by the fluid flow velocity through
the pipe 120, thus decreasing the TOF(1,2). Likewise, the velocity
of the ultrasonic signal traveling at the angle .theta. upstream is
impeded by the fluid flow velocity through the pipe 120, thus
increasing the TOF(2,1).
[0006] Specifically, the velocity of the first ultrasonic signal
traversing the path 135A is the sum of the velocity C of the
ultrasonic energy traveling through a stationary fluid of the type
traversing the pipe 120 and a velocity vector component v of the
fluid velocity U along the path 135A. U is the total velocity of
the fluid flowing parallel to the longitudinal axis of the pipe
120. That is, the total velocity of the first ultrasonic signal
traversing the path 135A of length L is equal to C+v. The TOF
T(1,2) is therefor: T(1,2)=(distance)/(velocity)=L/(C+v).
[0007] Likewise, the velocity of the second ultrasonic signal
traversing the path 135B is the difference between the velocity C
of the ultrasonic energy traveling through a stationary fluid of
the type traversing the pipe 120 and the velocity vector component
v of the fluid velocity U along the path 135B. That is, the total
velocity of the second ultrasonic signal traversing the path 135B
of length L is equal to C-v. The TOF T(2,1) is therefor:
T(2,1)=(distance)/(velocity)=L/(C-v).
[0008] The velocity C of the ultrasonic energy traveling through a
stationary fluid is a constant for the particular fluid flowing
through the pipe 120. Therefore, the measured T(1,2) and T(2,1)
provide the two equations, above, in the unknowns v and L. Solving
the two equations for v:
v = L 2 [ T ( 2 , 1 ) - T ( 1 , 2 ) T ( 1 , 2 ) * T ( 2 , 1 ) ]
##EQU00001##
[0009] However, the TOF measurements account only for the vector
component v along the measurement paths 135A and 135B of the fluid
flow velocity U. The entire fluid flow velocity U is equal to v/cos
.theta.. Thus:
U = L 2 cos .theta. [ T ( 2 , 1 ) - T ( 1 , 2 ) T ( 1 , 2 ) * T ( 2
, 1 ) ] ##EQU00002##
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a prior-art diagram illustrating a fluid-flow
measurement technique.
[0011] FIG. 2 is a diagram illustrating a fluid-flow measurement
device employing a single beam-forming ultrasonic transducer array
according to various example embodiments of the invention.
[0012] FIG. 3 is a diagram illustrating a fluid-flow measurement
device employing a single-dimensional beam-forming ultrasonic
transducer array according to various example embodiments.
[0013] FIG. 4 is a diagram illustrating a fluid-flow measurement
device employing a single two-dimensional beam-forming ultrasonic
transducer array according to various example embodiments.
[0014] FIG. 5 is a diagram illustrating a fluid-flow measurement
device employing a single convex three-dimensional beam-forming
ultrasonic transducer array according to various example
embodiments.
[0015] FIG. 6 is a diagram illustrating a fluid-flow measurement
device employing a single convex three-dimensional beam-forming
ultrasonic transducer array according to various example
embodiments.
[0016] FIG. 7 is a diagram illustrating a fluid-flow measurement
device employing a single beam-forming ultrasonic transducer array
configured as a two-dimensional sub-array attached to a
single-dimensional sub-array according to various example
embodiments.
[0017] FIG. 8 is a flow diagram illustrating a method of fluid flow
measurement according to various example activities.
[0018] FIG. 9 is a diagram illustrating a sequence of ultrasonic
beams associated with a fluid-flow measurement device implementing
a method of fluid flow measurement according to various example
activities.
[0019] FIG. 10 is a diagram illustrating a sequence of ultrasonic
beams associated with a fluid-flow measurement device implementing
a method of fluid flow measurement according to various example
activities.
[0020] FIG. 11 is a diagram illustrating a sequence of ultrasonic
beams associated with a fluid-flow measurement device implementing
a method of fluid flow measurement according to various example
activities.
[0021] FIG. 12 is a diagram illustrating a sequence of ultrasonic
beams associated with a fluid-flow measurement device implementing
a method of fluid flow measurement, including ultrasonic beam path
segments within a protected flow barrier according to various
example activities.
[0022] FIG. 13 is a flow diagram illustrating a method of fluid
flow measurement according to various example activities.
[0023] FIG. 14 is a diagram illustrating a sequence of ultrasonic
beams simultaneously emitted by a single beam-forming ultrasonic
transducer array associated with a fluid-flow measurement device
implementing a method of fluid flow measurement according to
various example activities.
[0024] FIG. 15 is a diagram illustrating an example sequence of
ultrasonic beams, each emitted at a distinct ultrasonic frequency
from a single beam-forming ultrasonic transducer array associated
with a fluid-flow measurement device implementing a method of fluid
flow measurement according to various example activities.
SUMMARY OF THE INVENTION
[0025] Apparatus and methods disclosed herein measure flow rates of
a fluid flowing through a pipe or tube using a beam-forming array
of ultrasonic transducer elements capable of mounting at a single
position at a wall of the pipe or tube. (The terms "pipe" and
"tube" are used synonymously within this disclosure.) A
beam-forming driver circuit operates in conjunction with the array
of ultrasonic transducer elements to provide directional control of
ultrasonic energy emitted from and received at the array. The
resulting ultrasonic beams are directed back to the single
ultrasonic array by a series of acoustic mirrors mounted to or
fabricated at known locations at an inside surface of the pipe.
Embodiments described herein are commercially advantageous in that
they employ a single ultrasonic transducer/transceiver unit rather
than multiple units. Doing so decreases costs associated with the
ultrasonic transducers themselves as well as costs of installation
in the pipe and post-installation calibration.
[0026] The beam-forming driver circuit selectively activates
transducer elements of the array to direct two or more outbound
ultrasonic beams through a fluid flowing through the pipe to one or
more acoustic mirrors. In some embodiments, the acoustic mirrors
are mounted at an inside wall of the pipe. The ultrasonic beams
travel along path segments of two types categorized by their effect
on the beam TOFs. A "measurement" ultrasonic path segment traverses
the fluid flow path at an angle of less than 90 degrees from the
pipe longitudinal axis and includes an upstream or downstream fluid
flow velocity component. A "non-measurement" path segment either
traverses the fluid flow path at an angle of 90 degrees from the
pipe longitudinal axis or is located near to the inside wall of the
pipe where the fluid flow velocity is substantially zero. In both
cases, non-measurement path segments effectively exclude upstream
and downstream fluid flow velocity components.
[0027] Fluid flow velocity along the fluid flow path and fluid flow
volume are calculated from TOF measurements as described in the
previously-presented example. In the case of the disclosed
apparatus and methods, however, contributions to TOF times from
known-length non-measurement path segments are subtracted from the
measured TOF totals. Doing so leaves the portions of the TOF
measurements attributed to measurement path segments from which to
calculate fluid flow velocities and volumes.
DETAILED DESCRIPTION
[0028] FIG. 2 is a diagram illustrating a fluid-flow measurement
device 205 employing a single beam-forming ultrasonic transducer
array 210 according to various example embodiments. The transducer
array 210 includes individually selectable ultrasonic transducer
elements and is capable of mounting at a single position at a wall
212 of a pipe 214. The fluid-flow measurement device 205 provides
directional control of ultrasonic energy emitted from and received
at the array of transducer elements 210 (e.g., the beam path
segments 220 and 224 associated with the beam path 220-222-224 and
the beam path segments 230 and 234 associated with the beam path
230-232-234).
[0029] The transducer elements of the single beam-forming
ultrasonic transducer array 210 may include bulk piezoelectric
transducer elements, capacitive micro-machined ultrasonic
transducer (CMUT) elements, piezoelectric micro-machined ultrasonic
transducer (PMUT) elements, or combinations thereof as further
described below
[0030] The fluid-flow measurement device 205 also includes a
beam-forming driver circuit 250 communicatively coupled to the
beam-forming ultrasonic transducer array 210. The beam-forming
driver circuit 250 selectively activates one or more first
sub-arrays of transducer elements of the array of transducer
elements 210 to direct two or more outbound ultrasonic beams
through a fluid flowing through the pipe. The ultrasonic beams
travel to and from one or more acoustic mirrors mounted at an
inside wall of the pipe (e.g., the acoustic mirrors 255 and 260
associated with the path 220-222-224 and the acoustic mirrors 255
and 265 associated with the path 230-232-234). It is noted that in
some embodiments, the acoustic mirror(s) may consist of a portion
of the inside wall of the pipe.
[0031] The beam-forming driver circuit 250 also selectively
activates one or more second sub-arrays of transducer elements from
the array 210 to sense a reflected return signal at a selected
angle (e.g., the reflected return signals along the beam path
segments 224 and 234 associated with each of the two outbound
ultrasonic beams along the beam path segments 220 and 230,
respectively.
[0032] In some embodiments, the first and second sub-arrays of
transducer elements may consist of the same elements and/or may
consist of all elements in the array of ultrasonic transducer
elements 210. Whether or not sub-arrays are used for directional
control of emitted and received ultrasonic beams depends upon
beam-forming techniques implemented by the array of ultrasonic
transducer elements 210 as controlled by the beam-forming driver
circuit 250.
[0033] Some beam-forming techniques, for example, may utilize a
first sub-array of elements to direct out-going beams along the
path segments 220 and 230. A second sub-array might be used to
listen for the first return signal from a direction of the
measurement path 224, and a third sub-array might be used to listen
for the second return signal from a direction of the measurement
path 234. Some embodiments may use phased-array techniques to
selectively energize individual elements and/or sub-arrays of
elements of the array of ultrasonic transducer elements 210 to
control beam lobe formation and thus beam direction. Individual
elements and/or sub-arrays of elements may be selectively energized
in one or more of time, frequency, phase, and magnitude domains,
among others.
[0034] The fluid-flow measurement device 205 also includes a
control and measurement module 275 communicatively coupled to the
array of transducer elements 210. The control and measurement
module 275 measures a TOF of each of the two or more ultrasonic
beams (e.g., the beams associated with the beam paths 220-222-224
and 230-232-234) from emission from the array of transducer
elements 210 to reception of the respective return signals at the
array 210.
[0035] The control and measurement module 275 calculates fluid flow
speed through the pipe 214 as a function of a difference in TOF
between the two beams traversing the first and second paths
220-222-224 and 230-232-234, respectively. At least a portion of
the difference in TOF results from an additive downstream fluid
flow velocity vector component along the measurement segment 224 of
the first path 220-222-224. Another portion of the difference in
TOF results from a subtractive downstream fluid flow velocity
vector component along the measurement segment 234 of the second
path 230-232-234. Both of the measurement segments 224 and 234
traverse the fluid at an angle less than 90 degrees from a
longitudinal axis of the pipe. In some embodiments, the first and
second path measurement segments 224 and 234 are of equal length
and the corresponding downstream and upstream fluid flow velocity
components are of equal magnitude and opposite direction.
[0036] In some embodiments of the fluid flow measurement apparatus
205, the acoustic mirror(s) may be configured to reflect one of the
ultrasonic beams in an upstream direction along the inside wall of
the pipe where the flow rate of the fluid is zero or substantially
zero and to reflect another one of the ultrasonic beams in a
downstream direction along the inside wall of the pipe where the
flow rate of the fluid is zero or substantially zero.
[0037] FIGS. 3-5 are diagrams illustrating the fluid-flow
measurement device 205 employing beam-forming arrays of ultrasonic
transducer elements 210A-210C according to various example
embodiments. The transducer arrays 210A-210C are formed as a
single-dimensional array, a two-dimensional array, and a
three-dimensional array, respectively. The array 210C of FIG. 5 is
formed as three-dimensional by adding convex curvature to the array
210B of FIG. 4.
[0038] FIG. 6 is a diagram illustrating the fluid-flow measurement
device 205 employing the convex three-dimensional beam-forming
ultrasonic transducer array 210C according to various example
embodiments. The array 210C is fitted at the pipe 214 and shows a
beam path (e.g., the beam path 230-232-234 of FIG. 2). Angular
differences between beam path emission from the array (e.g., the
beam path segment 230) and reception at the array (e.g., the beam
path segment 234) may be created by the convex curvature across the
array, electronic beam directional control as further described
below, or both.
[0039] FIG. 7 is a diagram illustrating the fluid-flow measurement
device 205 employing a single beam-forming ultrasonic transducer
array 210D according to various example embodiments. The array 210D
is formed as a plurality of sub-arrays of transducer elements
(e.g., a two-dimensional sub-array 710 abutted to a
single-dimensional sub-array 715). The plurality of sub-arrays of
transducer elements is capable of projecting ultrasonic beams along
beam path segments extending from and/or to the array 210D both
parallel to and perpendicular to the longitudinal axis of the pipe
214.
[0040] FIG. 8 is a flow diagram illustrating a method 800 of fluid
flow measurement according to various example activities. The
method 800 commences at block 810 with selectively activating
elements of an array of transducer elements capable of mounting at
a single position at a wall of a pipe (e.g., the array of
transducer elements 210 of FIG. 2). The transducer elements are
selectively activated at a first time to create a first ultrasonic
beam (e.g., the ultrasonic beam segment 220) directed toward an
acoustic mirror (e.g., the acoustic mirror 255). The acoustic
mirror is associated with a first series of acoustic mirrors (e.g.,
the series of acoustic mirrors 255 and 260).
[0041] The method 800 includes directing the first ultrasonic beam
along a first path (e.g., the path 220-222-224 of FIG. 2), at block
815. The first path includes one or more first path measurement
segments (e.g., the path measurement segment 224). The path
measurement segment traverses a fluid flowing through the pipe at
an angle less than 90 degrees from a longitudinal axis of the pipe.
The path measurement segment proceeds in a direction to include an
additive downstream fluid flow velocity vector component. The
method 800 also includes receiving a return of the first ultrasonic
beam at the array of transducer elements at a second time, at block
820.
[0042] The method 800 further includes creating a second ultrasonic
beam (e.g., the ultrasonic beam segment 230 of FIG. 2) at the array
of transducer elements, at block 825. The second ultrasonic beam is
directed toward an acoustic mirror (e.g., the acoustic mirror 255)
associated with a second series of acoustic mirrors (e.g., the
series of acoustic mirrors 255 and 265 of FIG. 2) at a third
time.
[0043] The method 800 continues at block 830 with directing the
second ultrasonic beam along a second path (e.g., the path
230-232-234 of FIG. 2). The second path includes one or more second
path measurement segments (e.g., the path measurement segment 234
of FIG. 2). The second path measurement segment traverses the fluid
flowing through the pipe at an angle less than 90 degrees from the
longitudinal axis of the pipe. The path measurement segment
proceeds in a direction to include a subtractive upstream fluid
flow velocity vector component. The method 800 also includes
receiving a return of the second ultrasonic beam at the single
array of transducer elements at a fourth time, at block 835.
[0044] The method 800 terminates at block 840 with calculating the
fluid flow speed through the pipe as discussed above in detail. The
fluid flow speed is a function of a difference in TOF between the
first and second ultrasonic beams. At least a portion of the
difference in TOF is a result of the additive downstream fluid flow
velocity vector component along the first path measurement segment
and the subtractive upstream fluid flow velocity vector component
along the second path measurement segment. In some implementations
of the method 800, the first and second paths are of equal length
and the downstream and upstream fluid flow velocity vector
components are of equal magnitude and opposite direction.
[0045] FIGS. 9-11 are diagrams illustrating example sequences of
ultrasonic beams generated by the fluid-flow measurement device 205
implementing the method 800. Some implementations of the method 800
include reflecting the first and second ultrasonic beams along the
inside wall of the pipe 214 where the flow rate of the fluid is
substantially zero. Examples include beam path segments 222 and 232
of FIG. 2; segments 922 and 932 of FIG. 9; and segments 1022, 1026,
1030, and 1034 of FIG. 10.
[0046] Some implementations of the method 800 include traversing
the first and second path measurement segments between the array of
transducer elements 210 and either a single acoustic mirror or an
inner wall of the pipe 214 opposite the array of transducer
elements 210 as illustrated in FIG. 11, paths 1120-1122 and
1130-1132.
[0047] FIG. 12 is a diagram illustrating a sequence of ultrasonic
beams associated with a fluid-flow measurement device 205
implementing the method 800, including ultrasonic beam path
segments within a protected flow barrier according to various
example activities. The method 800 may include reflecting
non-measurement path segments of the first and second ultrasonic
beams (e.g., the path segments 1222 and 1232) within an enclosed
channel 1250 formed along the inside wall of the pipe 214. Doing so
further isolates such non-measurement path segments of the first
and second ultrasonic beams from the fluid.
[0048] In some versions of the method 800, the first and second
paths may each include various types of path segments. Path segment
types include path segments orthogonal to the longitudinal axis of
the pipe (e.g., the path segments 220 and 230 of FIG. 2; the path
segments 924 and 934 of FIG. 9; the path segments 1020 and 1036 of
FIG. 10; and the path segments 1220 and 1230 of FIG. 12. Fluid flow
velocity components are zero or substantially zero along such
orthogonal path segments. The first and second paths may also each
include a segment extending along the inside wall of the pipe where
the flow rate of the fluid is substantially zero, as previously
described. Each path additionally includes one or more path
measurement segments (e.g., the path measurement segments 224 and
234 of FIG. 2; the path measurement segments 920 and 930 of FIG. 9;
the path measurement segments 1024 and 1032 of FIG. 10, the path
measurement segments 1120, 1122, 1130, and 1132 of FIG. 11, and the
path measurement segments 1224 and 1234 of FIG. 12).
[0049] Some implementations of the method 800 include traversing
the first path measurement segment between the array of transducer
elements and a first acoustic mirror and traversing the second path
measurement segment between the array of transducer elements and a
second acoustic mirror. (E.g., the path measurement segments 224
and 234 of FIG. 2; the path measurement segments 920 and 930 of
FIG. 9; and the path measurement segments 1224 and 1234 of FIG.
12.) Other implementations of the method 800 include traversing the
path measurement segments between acoustic mirrors (e.g., the path
measurement segments 1024 and 1032 of FIG. 10).
[0050] FIG. 13 is a flow diagram illustrating a method 1300 of
fluid flow measurement according to various example activities.
FIG. 14 is a diagram illustrating a sequence of ultrasonic beams
simultaneously emitted by a single beam-forming ultrasonic
transducer array 210 associated with a fluid-flow measurement
device 205 implementing the method 1300 according to various
example activities. Activities associated with the method 1300 are
described below with reference to the beam sequences illustrated in
FIG. 14.
[0051] The method 1300 commences at block 1310 with selectively
activating elements of an array of transducer elements capable of
mounting at a single position at a wall of a pipe (e.g., the array
of transducer elements 210 of FIG. 14). The transducer elements are
selectively activated at a first time to create first and second
ultrasonic beams (e.g., the ultrasonic beam segments 1420A and
1420B) directed toward one or more acoustic mirrors (e.g., the
acoustic mirror 1450). The acoustic mirror(s) are associated with a
first series and a second series of acoustic mirrors (e.g., the
series of acoustic mirrors 1450, 1455 and the series of acoustic
mirrors 1450 and 1460).
[0052] The method 1300 includes directing the first ultrasonic beam
along a first path (e.g., the path 1420A-1422A-1424A of FIG. 2), at
block 1315. The first path includes one or more first path
measurement segments (e.g., the path measurement segment 1424A).
The path measurement segment traverses a fluid flowing through the
pipe at an angle less than 90 degrees from a longitudinal axis of
the pipe. The path measurement segment proceeds in a direction to
include an additive downstream fluid flow velocity vector
component.
[0053] The method 1300 also includes directing the second
ultrasonic beam along a second path (e.g., the path
1420B-1422B-1424B of FIG. 14), at block 1320. The second path
includes one or more second path measurement segments (e.g., the
path measurement segment 1424B). The path measurement segment
traverses a fluid flowing through the pipe at an angle less than 90
degrees from a longitudinal axis of the pipe. The path measurement
segment proceeds in a direction to include a subtractive upstream
fluid flow velocity vector component.
[0054] The method 1300 further includes receiving a return of the
first ultrasonic beam at the single array of transducer elements at
a second time, at block 1325. The method 1300 also includes
receiving a return of the second ultrasonic beam at the single
array of transducer elements at a third time, at block 1335. Some
versions of the method 1300 differentiate the first and second
return signals based upon interference patterns created by the
return signals at the single transducer array, at block 1340.
[0055] FIG. 15 is a diagram illustrating an example sequence of
ultrasonic beams, each emitted at a distinct ultrasonic frequency
from a single beam-forming ultrasonic transducer array 210
associated with a fluid-flow measurement device 205 implementing
the method 1300 according to various example sequences. An
ultrasonic beam of frequency F1 traversing the beam path
1520F1-1522F1-1524F1 may be emitted at the same time as an
ultrasonic beam of frequency F2 traversing the beam path
1520F2-1522F2-1524F2. Some versions of the method 1300
differentiate the first and second return signals based upon the
ultrasonic frequencies of emission F1 and F2, at block 1345.
[0056] The method 1300 terminates at block 1350 with calculating
the fluid flow speed through the pipe as discussed above in detail.
The fluid flow speed is a function of a difference in TOF between
the first and second ultrasonic beams. At least a portion of the
difference in TOF is a result of the additive downstream fluid flow
velocity vector component along the first path measurement segment
and the subtractive upstream fluid flow velocity vector component
along the second path measurement segment. In some implementations
of the method 1300, the first and second paths are of equal length
and the downstream and upstream fluid flow velocity vector
components are of equal magnitude and opposite direction.
[0057] Apparatus, systems and methods described herein may be
useful in applications other than single sensor fluid flow
measurement. Examples of the apparatus 205 and the methods 800 and
1300 of single-sensor fluid flow measurement are intended to
provide a general understanding of the sequences of various methods
and the structures of various embodiments. They are not intended to
serve as complete descriptions of all elements and features of
methods, apparatus and systems that might make use of these example
sequences and structures. The various embodiments may be
incorporated into fluid flow systems for use in industrial,
petrochemical, medical, scientific, computer, and other
applications.
[0058] Apparatus and methods disclosed herein include a single
array of ultrasonic transducer elements mounted at a single
location at a surface of a pipe and associated driver and
measurement circuits to provide directional control of ultrasonic
energy emitted from and received at the array. The resulting
ultrasonic beams are directed back to the single ultrasonic array
by a series of acoustic mirrors mounted to or fabricated at known
locations at an inside surface of the pipe. Embodiments described
herein are commercially advantageous in that they employ a single
ultrasonic transducer/transceiver unit rather than multiple units.
Doing so decreases costs associated with the ultrasonic transducers
themselves as well as costs of installation in the pipe and
post-installation calibration.
[0059] By way of illustration and not of limitation, the
accompanying figures show specific aspects in which the subject
matter may be practiced. It is noted that arrows at one or both
ends of connecting lines are intended to show the general direction
of electrical current flow, data flow, logic flow, etc. Connector
line arrows are not intended to limit such flows to a particular
direction such as to preclude any flow in an opposite direction.
The aspects illustrated are described in sufficient detail to
enable those skilled in the art to practice the teachings disclosed
herein. Other aspects may be used and derived therefrom, such that
structural and logical substitutions and changes may be made
without departing from the scope of this disclosure. This Detailed
Description, therefore, is not to be taken in a limiting sense. The
breadth of various aspects is defined by the appended claims and
the full range of equivalents to which such claims are
entitled.
[0060] Such aspects of the inventive subject matter may be referred
to herein individually or collectively by the term "invention"
merely for convenience and without intending to voluntarily limit
this application to any single invention or inventive concept, if
more than one is in fact disclosed. Thus, although specific aspects
have been illustrated and described herein, any arrangement
calculated to achieve the same purpose may be substituted for the
specific aspects shown. This disclosure is intended to cover any
and all adaptations or variations of various aspects.
[0061] The Abstract of the Disclosure is provided to comply with 37
C.F.R. .sctn.1.72(b) requiring an abstract that will allow the
reader to quickly ascertain the nature of the technical disclosure.
It is submitted with the understanding that it will not be used to
interpret or limit the scope or meaning of the claims. In the
preceding Detailed Description, various features are grouped
together in a single embodiment for the purpose of streamlining the
disclosure. This method of disclosure is not to be interpreted to
require more features than are expressly recited in each claim.
Rather, inventive subject matter may be found in less than all
features of a single disclosed embodiment. The following claims are
hereby incorporated into the Detailed Description, with each claim
standing on its own as a separate embodiment.
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